News and knowledge of vision disorders are on the rise. It is estimated that the lifetime costs for all people with vision impairment who were born in 2000 will total $2.5 billion (2003 dollars, see generally, Centers for Disease Control and Prevention, Economic Costs Associated with Mental Retardation, Cerebral Palsy, Hearing Loss, & Vision Impairment, United States, 2003, MMWR 2004;53:57-9). These costs include both direct and indirect costs. Direct medical costs, such as doctor visits, prescription drugs, and inpatient hospital stays, make up 6% of these costs. Direct nonmedical expenses, such as home modifications and special education, make up 16% of the costs. Indirect costs, which include the value of lost wages when a person dies early, cannot work, or is limited in the amount or type of work he or she can do, make up 77% of the costs. These estimates do not include other expenses, such as hospital outpatient visits, emergency department visits, and family out-of-pocket expenses. The actual economic costs of vision impairment are, therefore, even higher than what is generally reported.
The most common causes of vision impairment among adults in the United States are age-related macular degeneration (AMD), presbyopia, diabetic retinopathy, cataracts, and glaucoma. AMD affects the part of the retina that is responsible for sharp central vision and is the leading cause of legal blindness in the United States in persons over 65 years old. According to a March 1997 Review of Optometry Journal, 10% of our population over age 52 has AMD and 33% of individuals over age 75 have AMD. It is estimated that more than 13 million Americans now have AMD and that, by the time the Baby Boomers reach age 65, there will be over 30 million cases of AMD, almost 25% of our population over 65.
Presbyopia is a frustrating condition that begins to effect the “small print” visual acuity (i.e., blurred vision) of many individuals after they reach forty years of age. People find that they are unable to focus on the small print, and may develop headaches, eyestrain, or feel fatigued. Treatment typically involves buying inexpensive, “off-the-shelf” “reading glasses”, surgery, or bi-focal contact lenses. It is believed that presbyopia occurs from a loss of elasticity or flexibility in the natural lens of the eye of those over forty years of age. During the age-related process, the proteins in the lens begin to make the lens harder, less elastic, with muscle fibers around the lens also effected. As the lens requires elasticity to focus up close, with a diminished or diminishing functionality, visual acuity is impacted.
Diabetic retinopathy is a common complication of diabetes in which the blood vessels in the retina break down, leak, or become blocked, leading to vision impairment. Cataracts are a clouding of the eye's lens, which is normally clear. Glaucoma is increased fluid and pressure within the eye that leads to enlargement of the eyeball. The risk of vision loss from many of these conditions can often be reduced if the condition is found early and treated.
Normal retinal cell function is a photochemical reaction converting light energy to an electrical impulse which travels to the brain and vision occurs. With AMD and other visual system diseases, diseased, inflamed retinal cells eventually lose cell function. Adenosine triphosphate (ATP) levels drop, protein synthesis drops, the electrical resistance goes up, and cell electricity potential goes down. Basically, the cells seem to go dormant for a time before they die. It is believed that, if electrical stimulation is provided to the cells before they die, blood vessel permeability is increased, a more normal cellular electrical potential will be achieved, the ATP levels will increase, protein synthesis will occur again, and normal cell metabolism will be restored.
Additionally, electrical stimulation appears to have a healing effect on the small blood vessels in the retina, promoting a more efficient delivery of nutrients to the retinal cells and a more efficient uptake of proteins that can accumulate on the retina. Thus, it is believed that microcurrent stimulation (i.e., the delivery of typically about less than 1,500 microamps) will help rejuvenate the cells in the retina to slow or stop degeneration of the eye due to AMD and the like. With the proper microcurrent stimulation wave form and therapy procedures, progressive vision disorders may be slowed or stopped in a large number of people suffering therefrom.
For example, Fedorov et al., U.S. Pat. No. 5,147,284, proposed to treat diseases of the optic nerve and retina by the application of a pulsed 3.5 magnetic flux, the magnetic field induction being from 0.1 T to 0.25 T. However the technique is invasive, requiring exposure of the posterior portion of the eyeball and optic nerve and introduction of the inducer into the orbit.
Liss et al., U.S. Pat. No. 4,614,193, proposed to treat glaucoma with the application of transcutaneous electrical stimulation, more particularly, the application of pulsed electrical current at a level less than 4 milliamperes, the pulse trains occurring at 12-20 kHz, amplitude modulated at 8-20 hz, and having a 3:1 duty cycle. Applying this waveform through electrodes positioned on the temple and on the ipsilateral hand, Liss et al. achieved an approximately 28% reduction in intraocular pressure in the treated eye. To the knowledge of the inventor, passage of electrical current through the eye, hereinafter “transocular electrical conduction,” has been used in the art for the treatment of blindness disease, but has yet to be maximized as a vision disorder therapy, as for example, via the selection and/or combination of wave forms, power, duration, and frequencies.
Greenberg et al., U.S. Pat. No. 5,944,747, is generally directed to a method of focused phosphene generation through deeper intermediate retinal cellular electrical stimulation, to the exclusion of direct galleon cellular electrical stimulation, via the application of a long duration stimulation signal. Preferably, the long duration stimulation signal is a biphasic signal having a negative and positive phase pulse. It is further believed to be advantageous to make such biphasic pulses simulate cathodic monophasic pulses by using unequal amplitude phases.
It is suggested from Wallace et al., U.S. Pat. No. 5,522,864 that a direct current with a constant magnitude of 200 microamps has show positive effect in treating ocular disease including macular degeneration. Further, Jarding et al., U.S. Pat. Nos. 6,035,236 & 6,275,735, suggests that microcurrent stimulation, vis-a-vis the application of microcurrent approximate to an eye wherein the microcurrent has an amplitude of about 50-180 microamps and comprises a sweep wave microcurrent signal produced by a sweep wave signal generator, can improve vision in individuals suffering from additional “blindness” causing diseases, including retinitis pigmentosis. In these instances, the theory for improvement has to do with bringing energy to dormant photo-receptor cells. The inventor believes that the Wallace et al. effort is not expansive enough in both varying the power level and frequency selection/application duration, and further, that the Jarding et al. efforts are too broad in not specifying especially effective therapeutic frequencies. In the Jarding et al. case, this may be due to Jarding et al. attempting to treat a broad range of diseases including cancer which likely require technical considerations that are different from those implicated in overcoming vision disorders.
Thus there remains a need for an energy based treatment of vision disorders that maximizes therapeutic effect. Furthermore, it is believed advantageous to provide an energy based treatment that includes electrical, light and sound energy forms, alone or in select combination, to effectuate a therapeutic result in persons suffering from vision disorders. Further still, it is believed that improvements in transocular electrical conduction are achieved utilizing specific frequencies, wave forms, durations, and power algorithms in furtherance of maximizing subject visual efficacy.